Talk:Sun/Archive 4

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Life Cycle Image

I believe the image of the suns life cycle is slightly incorrect because the "Now" arrow is more towards 4.5 billion years old, while the earth is about 4.4 billion years old, the sun is more towards 5 billion years old. Gemroth (talk) 00:09, 18 March 2008 (UTC)

Adding to that,

Hotly debated theory cited as fact.

'In fact, even during its life in the main sequence the Sun is gradually becoming more luminous, its surface temperature slowly rising. The increase in solar temperatures is such that in about 900 million years, the surface of the Earth will become too hot for the survival of life as we know it.[31] After another billion years the surface water will have completely disappeared.[32]'

Anon 03:57, 24 April 2008 (GMT)

Life Cycle

The "Life Cycle" section contains :-

"Each second, more than 4 million tonnes of matter are converted into energy within the Sun's core, ...". That is true : but it seems to me capable of being misunderstood, by those of inadequate sagacity, as meaning that about 4 million tonnes of hydrogen are consumed per second. See, for example, http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2008/03/01/nsky01.xml paragraph 4.

In the "Core" section, we see "About 3.4 × 10³⁸ protons (hydrogen nuclei) are converted into helium nuclei every second"; but the ordinary reader will not rapidly perceive that, since the AMU is 1.66 × 10⁻²⁷ kg, the mass of hydrogen uses is about 565 million tonnes per second.

I suggest that the second paragraph of "Life Cycle" be rephrased to include both the 4 million and the 565 million, for clarity. But check the exact numbers.

The page does not appear to be editable by me.

82.163.24.100 (talk) 10:29, 3 March 2008 (UTC)

The page is not editable by you, because it is semi-protected. I suggest getting an account, which will allow you to edit semi-protected articles such as this one.

What you say does make sense to me, but I'm not sure about the 585 figure - I cannot find a source to confirm that. [1] says that it's actually 685 million. I think that an off the cuff calculation like that would be considered "original research", and be quickly edited out of the article if there is not a scholarly source added to confirm it. MichelleG (talk) 13:24, 4 March 2008 (UTC).

Surface Area

Is wrong. That is the value for km^2, not m^2, it should be roughly 6x10^18 m^2. I checked the reference, and its wrong there too, but just do the maths on the diameter. SA = 4*pi*(r^2)

Cheers,

Taffy —Preceding unsigned comment added by 62.31.163.74 (talk) 22:22, 6 March 2008 (UTC)

I was just going to say the same thing, except the given value is correct in units of m*km, not km^2 = 10^6 m^2 ( which is a clue to the cause of the error. )

It got my attention because of the "citation needed" notation on the mass conversion rate. This value is just a restatement of the luminosity in units of kg/sec = watts/c^2, to the one significant figure given. It reflects a presumption of equilibrium between the luminosity and the total solar power.

I noticed that the given luminosity is pi*1000 times the given solar area * given mean intensity, instead of the required factor of pi. I was surprised to notice that the discrepancy was in the given area.

68.77.25.250 (talk) 03:27, 22 March 2008 (UTC)

does sol=Sun?

Please could I have some help?

A website was giving information about 'sol'. Does that mean the sun?

from KT.Woot

KT.Woot (talk) 19:31, 17 March 2008 (UTC)

Sol is a name for the Sun. Not commonly used, though, in science or out. Saros136 (talk) 19:52, 17 March 2008 (UTC)

From the Latin, no? Certasinly its the Spanish/Portuguese word for the Sun. Thanks, SqueakBox 01:11, 20 March 2008 (UTC)

It is the Latin name for the sun yes and as such is also where the adjective Solar (system) comes from, and like Luna (ad. Lunar) for the moon is the main equivalent to the english names. Terrasidius (talk) 14:36, 31 March 2008 (UTC)

Volume

The unit of the volume seems to be wrong. From the source cited (NASA) we can see that the actual volume is 1.412 x 10^18 km^3, that is 1.412 x 10^27 m^3 and not 10^21. 99.241.94.222 (talk) 13:59, 30 March 2008 (UTC)

Indeed. I made the correction (at Template:Solar System Infobox/Sun). ASHill (talk) 20:49, 30 March 2008 (UTC)

Location section

I have created a new section titled "Location within the galaxy," since I was disappointed to find that this info was not currently in the article. For now, I have simply copied the wording from the "Sun's Location" section of the Milky Way article. This subject matter is a little out of my field, though I'm sure more qualified editors will add and make changes to it. --Jleon (talk) 04:06, 14 April 2008 (UTC)

Contradictions

there seem to be lots of contradictions in this piece e.g.

overview “This is suggested by a high abundance of heavy elements such as gold and uranium in the solar system. ……..

No mention of these in the Photospheric composition listed in adjacent table. Presumably this is because here you are referring to the whole solar system and not just the Sun. In that case it would be helpful to explain why the planets have the heavy metals but the sun does not if they are all derived from the same source.

Similarly further down in Chemical composition Element abundances According to Bahcal (1990)[42] cited in Thoul (1993:15),[43] the characteristic mass fractions of some elements are: Hydrogen: 34% Helium: 64% Oxygen: 1% I.e. 99% are the above . So where are the heavy metals?

Also

Location within the galaxy The Sun may be found close to the inner rim of the Galaxy's Orion Arm, in ....

To a novice this is a little confusing Perhaps: The Sun is one of many stars in the Galaxy called the Milky Way. Within this Galaxy it is found etc etc Cmlawrence (talk) 11:35, 14 April 2008 (UTC)

Re gold and uranium: heavy elements are present only in trace amounts in any star, including the Sun, and aren't among the 10 most abundant elements. However, all heavy elements are more abundant in the Sun than in low metallicity (heavy element abundance) stars. I've (hopefully) clarified that point. ASHill (talk) 22:27, 16 April 2008 (UTC)

the moon is made out of cheese and the sun is made out of tomatoes and hot sauce —Preceding unsigned comment added by 98.240.223.248 (talk) 00:38, 29 April 2008 (UTC)

The Ultimate Fate of the Sun / Solar System

I was thinking that this could be filled this under the Life cycle section, however I feel that this should have its own section.

While many discuss the ultimate fate of the sun as simply the sun turning into a red giant in about 5-6b years and in about 10b years the sun expected to have totally exhausted its fuel, a much larger event looks very likely to occur in about 3 billion years [2] when the Milky Way and the Andromeda Galaxy's pass very close, possible through each other. [3].

This can create many different possibilities. Here are a few.

1- the sun thrown out of the galaxy by gravitational effect into the deep void of the universe

2- the sun thrown out of the galaxy by gravitational effect, however the velocity isn't great enough to have escaped the gravity of the Milky Way's central black hole. This will eventually cause the sun to be pulled back towards the black hole, passing through much hotter, denser gas that surrounds the black hole, and possibly passing very close to the back hole, thrown into the opposite direction into a possible erratic orbit.

3- the sun is thrown out but it is caught by the gravity of Andromeda's black hole.

4- the sun could pass too close to either of the black holes and get caught in the event horizon.

5- when the 2 Galaxies pass each other, major star formation will occur creating many more super massive or hyper massive stars with short lives. The effect of these massive supernova and hypernova explosions could greatly effect the sun in some way.

6- when the two galaxies eventually merge creating a massive super hot elliptical galaxy, two massive black holes will orbit close around each other and possibly merge. Now if the sun was lucky to survive the merger, what effect would these have on the sun?

There are other possibilities, however it is almost certain that the sun will enter a period of severe disruption which possibly could lead to its destruction and I would like this topic to be discussed and eventually be entered into the main article.

This could also be file in under the solar system, as it's future will also be greatly effected by the galactic collision long before the sun turns into a Red Giant. --anon 87.192.200.169 (talk) 15:10, 1 May 2008 (UTC)

None of these—even if they do occur—are actually likely to significantly affect the Sun because we're very unlikely to pass near enough to any system in either galaxy, particularly the center of Andromeda, given the vast size of each galaxy. See Formation and evolution of the Solar System#Galactic evolution for a discussion of the likely effect on the Solar System of the collision between the Milky Way and the Andromeda Galaxy. ASHill (talk) 20:55, 1 May 2008 (UTC)

Age

This article claims Sun's age is about 4-5 billion years. But the earth article claims similar age. Does that mean both celestial objects were born concurrently, independently? It is impossible.Anwar (talk) 20:07, 7 May 2008 (UTC)

Concurrently, but not independently. Formation and evolution of the Solar System. ASHill (talk | contribs) 20:10, 7 May 2008 (UTC)

Sun picture Viewer Mars to Sun (Image 15)

• http://www.welt.de/wissenschaft/article2033800/Nasa_schwaermt_von_perfekter_Phoenix-Mission.html

194.66.226.95 (talk) 09:26, 27 May 2008 (UTC)

The end of life on Earth Contradictions 500 million years? 1 billion years? 1.9 Billion years?

I am a little confused as to what the information on this article and the Earth article says about the end of life on Earth. It says that in 900 million years all plants on Earth will die and in an additional 1 billion years all of the water on Earth will evaporate. Does this mean that in 1.9 billion years the Earth's ocean will evaporate? It is confusing because the sources say in 1 billion years the Earth's oceans will evaporate but the article says a billion years later, meaning after 900 million years the oceans will evaporate. So is it 1 billion years or 1.9 billion years that the Oceans will evaporate. Another thing is that on the Earth article it says also that in only 500 million years all life on Earth will die but this contradicts the place where it says that in 900 million years all plants will die and millions of years later on animals will die. I am so confused by these contradictions. Please help clarify this for me.Maldek (talk) 01:15, 19 June 2008 (UTC)

The 1.9 billion number was made up; it wasn't in any of the sources. However, there is considerable uncertainty in precisely when the Sun will become too hot for water to exist on the Earth's surface (probably the best criterion for the possibility of life); around a billion years is probably the best estimate, and we really shouldn't try to be any more precise than that. I've updated the section to bring it in sync with the relevant main article, formation and evolution of the Solar System. ASHill (talk | contribs) 23:59, 19 June 2008 (UTC)

Images

Sorry to barge in, the images in the article may have been selected on excellent grounds. However, I found Image:STEREO-B_solar_eclipse.jpg and Image:Mass_eject_in_ultraviolet_light.jpg and to my untrained eye they look superior to some of those in the article. Thought you might consider them for inclusion. Dhatfield (talk) 23:21, 19 June 2008 (UTC)

Was bold - made the edits I thought appropriate. Please check wording of captions for accuracy. Dhatfield (talk) 00:07, 20 June 2008 (UTC)

The Sun becomes a Red Giant in 5.43 billion years.

The Sun is 4.57 billion years old, as confirmed in this article. and will spend 10 billion years as a Main Sequence Star before it becomes a Red Giant. Is it okay to change 5-6 billion years to a more accurate 5.43 billion years? Thank You.Maldek (talk) 04:40, 20 June 2008 (UTC)

See my reply in one of the (at least) two other places you made this comment. Short answer: no. ASHill (talk | contribs) 13:37, 20 June 2008 (UTC)

Core figures discrepancy

There is a dual discrepancy in the figures of core radius, density, energy output and specific power figures, per volume and per mass units each. Using the figures from the article rounded to 2 decimals: the solar radius is 7.0×10⁸ m, the core radius is 0.2 total radius, total core power is 3.8×10²⁶ W. This yields the volume of the core of 1.1×10²⁵ m³, and its specific power of 33 W/m³. The article gives 0.3 μW/cm³ (note that 1 μW/cm³ is the same as 1 W/m³), 100 times less. Next, given the average density of the core of 1.5×10⁵ kg/m³, find the average power per kg be 3.8×10²⁶ W / (1.1×10²⁵m³ × 1.5×10⁵ kg/m³)) = 2.3×10⁻⁴ W/kg = 230 μW/kg, while the article cites 6 μW/kg, this time 38 times less.

I am only reporting the discrepancy, as, lacking a reliable source for solar core physical parameters, I am unable to sensibly correct the article at the moment.

— Fregimus (talk) 09:54, 26 June 2008 (UTC)

Luminosity figure discrepancy

To the best of my knowledge, the value for luminosity should be 3.826×10²⁶ watts and not 3.846×10²⁶ watts. There are two different arguments supporting my view.

First: The text cites a mass conversion rate of 4.26 million tons per second which is equivalent to 4.26×10⁹ kg/s. Multiplying this by 2.99792458×10⁸ m/s squared the result is 3.828697×10²⁶ W.

Second: If the lumen output, given as 3.75×10²⁸ lm, is divided by the luminous efficacy of 98 lm/W, a value of 3.82653×10²⁶ W is obtained.

Therefore, I consider the listed value of 3.846×10²⁶ watts for the luminosity to be in error. I truly hope the staff in charge of this outstanding article performs some checking and decides whether if the changes apply.

— Burst3 (talk) 18:36, 07 July 2008 (UTC)

The current value looks to be accepted. For example, this paper (DOI:10.1086/321493: section 2.1) reports that the current best estimate is 3.842, with estimates disagreeing at the 0.2% level. The 3.846 value currently used in Sun is cited, so it shouldn't be changed without reliable sources that contradict the reliable sources arguing for 3.84. (However, I could see chopping one sig fig off, so we only report 3.84 10²⁶ W.) ASHill (talk | contribs) 19:31, 7 July 2008 (UTC)

Comparison of how big the sun appears when seen from the surface of different planets.

I created an image named "Comparison_sun_seen_from_planets.svg‎" (http://upload.wikimedia.org/wikipedia/commons/d/df/Comparison_sun_seen_from_planets.svg). The headline already says what it shows. The image is uploaded to CC and can be added if found useful. The German version of this article is unprotected so you can watch it "in action". :) I used the lens equation with an arbitrary value for the distance eye-lens <-> retina, then normalized the results. Nevermore4ever (talk) 17:16, 18 July 2008 (UTC)

Solar Cycle references

The article states: "Solar activity minima tend to be correlated with colder temperatures, and longer than average solar cycles tend to be correlated with hotter temperatures."

I'd like to see a reference for this info. —Preceding unsigned comment added by Kdconod (talk • contribs) 21:02, 24 July 2008 (UTC)

Chemical composition

This section is almost impossible to read and makes little sense to the layman. Could somebody please write it in more accessible language? AJKGORDON«» 13:54, 28 July 2008 (UTC)

Yeah, that's bad. I'll try to work on it. (Finding references for Solar abundances is actually annoyingly tricky, so it may take me a bit of time to clean it up.) —Alex (ASHill | talk | contribs) 14:11, 28 July 2008 (UTC)

Thank you. AJKGORDON«» 18:11, 28 July 2008 (UTC)

I've rewritten the section (diff). The new version is much shorter. Much of the material in there was probably not worth saving at all, but some discussion of diffusion is perhaps warranted, although a separate article (something like Chemical composition of the Sun) is probably a better place for that level of detail. —Alex (ASHill | talk | contribs) 01:52, 30 July 2008 (UTC)

I disagree. The material in there needed to be saved. I'll give a try at a rewrite. Headbomb {ταλκ – WP Physics: PotW} 02:37, 30 July 2008 (UTC)

Well it seems I can't make much sense of the source material. I've kept things reverted as someone else may succeed where I've failed. Feel free to return to Alex Ashill's version. Headbomb {ταλκ – WP Physics: PotW} 03:04, 30 July 2008 (UTC)

My intent was not to necessarily permanently remove all the topics, but the chemical composition section as it was was essentially unreadable and useful as little more than a collection of largely-outdated references. I tried to write a coherent, readable summary. I would be happy to see the topics that sort-of-existed before discussed in a readable manner as well, but the subsections all need to be rewritten essentially from scratch (which is why I deleted them all). In the meantime, I'll revert to my version.

The sources cited are quite technical; a good review article is probably a better place to go. —Alex (ASHill | talk | contribs) 03:14, 30 July 2008 (UTC)

The article of Lodders et al. 2003 (and some references therein) (see ref 59 in Uranus) should be cited instead of old papers from the 70-th. Ruslik (talk) 07:00, 30 July 2008 (UTC)

The section abut the composition of the sun is flawed: "The most abundant metals are oxygen (roughly 1% of the Sun's mass), carbon (0.3%), neon (0.2%), and iron (0.2%).[45]" —Preceding unsigned comment added by 195.222.17.101 (talk) 20:00, 22 September 2008 (UTC)

Why? I don't know if the numbers are quite right, but I suspect you are confused about the use of the word "metal". For astronomers, everything heavier than Helium is a metal, thus the sentence is technically ok. See Metallicity. It might be better to formulate this in a way more friendly to lay readers, though. --Stephan Schulz (talk) 20:12, 22 September 2008 (UTC)

Give that the immediately preceding sentences are "The Sun is composed primarily of the chemical elements hydrogen and helium[....] All heavier elements, called metals in astronomy, account for less than 2 percent of the mass", I think this is adequately explained. The use of the term "metals" in astronomy is confusing, but I think it really does simplify and clarify the discussion of chemical composition. I'm very open to suggestions for clarifying that section, of course. —Alex (ASHill | talk | contribs) 20:28, 22 September 2008 (UTC)

Didn't know that, thanks for the clarification. Maybe you can add a link to the metallicity article? Thanks. —Preceding unsigned comment added by 195.222.17.101 (talk) 10:22, 24 September 2008 (UTC)

The word "metals" is a link to the metallicity article. —Alex (ASHill | talk | contribs) 13:21, 24 September 2008 (UTC)

Color of the Sun

The uncited comment about the color of the Sun appearing yellow because the blue light is scattered in the sky (also explaining why the sky is blue) seems to be, at best, in dispute. I could not find a definitive reference in support of this, and my search found at least one dissenting opinion (the book "Bad Astronomy" by Philip C. Plait, 2002) which claims that the amount of blue light that is scattered is not enough to account for the perceived color shift. Is there a definitive reference that shows that the reason given here is correct? If not, I'd recommend rewriting or removing that claim. 71.164.160.112 (talk) 22:39, 19 August 2008 (UTC)

I found a reference that supports the claim and have added it to the article thanks for pointing it out! Skeletor 0 (talk) 17:30, 9 September 2008 (UTC)

Should it be 'The Sun'

A minor point, perhaps, but whenever we refer to this body, we always say 'The Sun', not 'Sun'. Note the heading above the image at the top of the page. I know there is an article called 'The Sun', for the UK newspaper. But that could become 'The Sun (newspaper)'.

Similarly with 'The Moon' - but unlike 'Earth' (although we sometimes say 'The Earth' but it doesn't sound right) and Mercury etc. The article does redirect when using the search term 'The Sun', but I think the article should be 'The Sun' and users should be redirected to it if they put in 'Sun'. —Preceding unsigned comment added by Jackins (talk • contribs) 10:41, 19 September 2008 (UTC)

No. See WP:MOS#Article_titles and WP:NAME. Articles are avoided unless part of a proper noun. Also, while my "we" may be different then your "we", we do not always use the name with the article, e.g. in "Our sun is a normal yellow dwarf". --Stephan Schulz (talk) 11:13, 19 September 2008 (UTC)

i cant edit

...but i think Sunlight should go in the 'see also' section, (cos' it's relevant to those still here on this planet) . 79.76.146.25 (talk) 03:19, 24 September 2008 (UTC)

I added a wikilink to sunlight in the introduction to the article. The normal policy on Wikipedia is to avoid adding links to the 'see also' section that are included in the main text. Thanks for the suggestion, and please do create an account and make any edits you feel appropriate! (Normally, anyone can edit Wikipedia articles, but this article gets so much traffic and vandalism that editing without an account is disabled.) —Alex (ASHill | talk | contribs) 13:21, 24 September 2008 (UTC)

Song Of The Sun

Bob Thomas and Huw Pudner have written "Song For The Sun" in a folk style ballad. Probably inspired by the heavy and persistent rain that fell in August 2008 and with inspiration from" The Worm Forgives The Plough" by John Stewart Collis. —Preceding unsigned comment added by 82.11.213.153 (talk) 15:22, 29 September 2008 (UTC)

Candle releases more energy than the Sun ?!

The article says:

This actually corresponds to a surprisingly low rate of energy production in the Sun's core—about 0.3 W/m³ (watts per cubic meter). This is less power than generated by a candle.

Obviously should be "less power per volume than that generated by a candle". And it's not low rate of energy production but low power to volume ratio. And the (watts per cubic meter) parenthesis comment is silly - if anyone knows what watts per cubic meter means then he would surely know what W/m³ means also.

Age of Sun, of Galaxy and of Universe

It seems disproportionate to assume the ages of either the Milky Way galaxy, other galaxies, and the universe should all be so close to the estimated age of the Sun when evidence in the form of short-lived isotopes such as lithium, which are consumed with great rapidity, are found abundantly in stellar spectra of hot blue stars forming in the 'stellar nurseries'. Moreover, many stars are found in the Hertzsprung-Russel diagram which are much older than the Sun.

It is more likely the Sun's entire existence is not in the center of the time of existence of the Galaxy and certainly not in that of the entire universe. To put it more carefully, the Sun's existence is not in the center of space-time.

SyntheticET (talk) 16:43, 20 October 2008 (UTC)

Updates / Alterations

I think the description in the first section of this article about the "surface spectral composition" of the Sun is misleading as it implies that the Sun has a solid surface which is factually incorrect. It would be more appropriate to say the spectral composition of the photosphere is ... and then provide a link to the photosphere section of the article.

Secondly recent research has actually re-established the possibility of the Earth being swallowed up during the Sun's red giant phase, and this should be included. reference for this:

Monthly Notices of the Royal Astronomical Society (DOI: 10.1111/j.1365-2966.2008.13022.x)

Thanks,

Gaz —Preceding unsigned comment added by 144.124.16.28 (talk) 13:25, 27 February 2008 (UTC)

The discussion of plasma in the structure section comes out of nowhere. I would fix it but the article is semi-protected. —Preceding unsigned comment added by 68.13.192.233 (talk) 03:51, 8 October 2008 (UTC)

If one were to observe it from Alpha Centauri, the closest star system, the Sun would appear to be in the constellation Cassiopeia.

This sentence, the final line of the section "Solar Space Missions", seems irrelevant to me. The position of the Sun viewed from another star system says nothing at all about the nature of the Sun, and its not a particularly interesting piece of trivia. Perhaps in should be included in the article about Alpha Centauri, but its inappropriate here, in my opinion. FiatLux23 (talk) 08:53, 22 October 2008 (UTC)

Agreed. I think the statement is too specifc to be valid on the sun page Suntanman (talk) 17:41, 24 October 2008 (UTC)

Peace

We are all children of the sun, we all came out of the sun so why do we fight? We all came from one source. —Preceding unsigned comment added by 79.72.91.250 (talk) 21:47, 8 October 2008 (UTC)

Well, here's your ticket back. Bon yoyage! Myles325a (talk) 01:59, 26 December 2008 (UTC)

Make a wish and send it to the sun. You can only use it for good ;) —Preceding unsigned comment added by UnionWorker (talk • contribs) 05:19, 1 February 2009 (UTC)

Extent of hydrogen/helium ionization

I'm in astro 320 at U of Alberta (MT tomorrow :)) and I am confused about the reason why hydrogen is ~100% ionized in Sun's core (T = 1.57*10^7 K; ref. my assignment). To calculate N(II)/N(total), I calculated N(II)/N(I) using the Saha eqn (using electron density = 6.1*10^31 m^-3), and found N(II)/N(total) by noting that: N(total) = N(I) + N(II). Also, I used partition functions, Z(H(I))=2 and Z(H(II)) = 1 (no degeneracy for proton). Anyway, I calculated that N(II)/N(total) = 0.709, or 70.9%. This calculation neglected helium (all hydrogen in sun), but helium would lower hydrogen ionization energy by compressing H's orbitals (is this right? or would it raise the I.E.?) from 13.6 eV, which (I think) would, if lowered, increase the calculated fraction. Conversely, He is also ionized (III or II) producing more `free` electrons to reduce the fraction of ionized Hydrogen. Are there other effects to account for the 100% ionization. —Preceding unsigned comment added by Bizarrini (talk • contribs) 01:20, 15 October 2008 (UTC) - Why hasn't anyone tried to answer my question yet? It's been months... —Preceding unsigned comment added by 75.159.7.47 (talk) 07:22, 3 January 2009 (UTC)

I'd recommend you to check out the standard undergrad astrophysics text: Carole and Ostlie's Modern Astrophysics. I'm sure I've found an answer in there but can't seem to find it today. Good luck! —Preceding unsigned comment added by 71.163.63.205 (talk) 21:38, 25 January 2009 (UTC)

Faint young Sun vs. life cycle

Neither the faint young sun subsection nor the Faint young sun paradox article addresses the fact that the Sun was probably significantly more massive at the time (due to the blowoff by the solar wind in the intervening period, as mentioned elsewhere in the article -- though in connection with the future). This would result in an earth orbit closer to the Sun, thus offsetting the lower intrinsic solar brightness. The radius of the orbit is roughly inversely proportional to the Sun's mass, while the solar flux intercepted at earth's orbit is inversely proportional to the square of the orbit radius. So, if the solar mass was roughly 20% bigger than today, that would have completely compensated for the lower, 70% luminosity. Even if the mass difference was smaller -- understanding that the solar wind was probably less intense than today or in the future due to the lower luminosity, it seems this effect could still have been a significant contributor to the liquid water, in addition to possible greenhouse gases mentioned elsewhere. Are there any references as to how much mass has been blown off from the Sun since it was formed or containing a discussion of this effect?24.58.175.197 (talk) 21:47, 31 October 2008 (UTC)john wilkinson

In a billion years, the current solar wind will remove 0.003% of the solar mass. Later the sun will start to shed mass much more rapidly, but in the current phase of its evolution, the mass change is negligible. Dragons flight (talk) 01:10, 1 November 2008 (UTC)

Needs sources

For an FA quality rating, this article seems to have a lot of material that is not sourced. Would it be possible for references to be added, as appropriate, so as to avoid a future FAR? Thank you.—RJH (talk) 20:54, 28 November 2008 (UTC)

Mass of Sun

What is the exact mass of the sun in KG? I guessed something like 1456136933221566562465252,7179234 KG... —Preceding unsigned comment added by 82.168.235.93 (talk) 16:05, 5 January 2009 (UTC)

Well if you read the article and look at the source of the value given for the mass of the sun it takes you to: http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html which says 1,989,100 x 10²⁴ kg. Which should be good enough value for any calculation you are doing unless you want a lot of precision, and even if you want that, if you think about it the sun is loosing mass all the time by converting it to energy in huge amounts and blowing it off in solar wind, so the mass is constantly decreasing.Ergzay (talk) 12:33, 7 January 2009 (UTC) is theory using theory for the assumptions of the model this data proposes to be correct. Any data written about the sun, other than the frequencies and amplitudes of the energy waves passing through the media between the sun and earth, is little more than speculation. why print it ? to waste the valuable time of the goyim child ?

Speed of the Sun Around the Galaxy

{{editsemiprotected}} According to "Milky Way a Swifter Spinner, More Massive, New Measurements Show" (http://www.cfa.harvard.edu/press/2009/pr200903.html) by the Harvard-Smithonian Center for Astrophysics on January 05, 2009, the new distances and speeds are as follows:

- 28,000 light-years from the Milky Way’s center
- 600,000 miles per hour (My manual conversion: 268 km/s)

Klabbas (talk) 23:27, 7 January 2009 (UTC)

Question: The current distance is given to 3sf with standard error. Can you find the accurate data which the article references? haz (talk) 14:11, 8 January 2009 (UTC)

Not done: No response to query.--Aervanath talks like a mover, but not a shaker 21:24, 19 January 2009 (UTC)

I have contacted the article authors, and received a response from Mark Reid. In short, he says, "A paper documenting the results in the press release is being drafted and hopefully will be submitted within about 1 month. Following refereeing, which usually takes 4-6 weeks, it should appear on the Astro-ph preprint server."

He did go on to supply some of the detail (where "Ro is the distance to the Galactic Center and To is the circular rotation speed of the Galaxy at the location of the Sun."):

We are using the NRAO Very Long Baseline Array (VLBA) and the Japanese VERA project to measure trigonometric parallaxes and proper motions of masers found in high-mass star-forming regions across the Milky Way. Early results from 18 sources locate several spiral arms. The Perseus spiral arm has a pitch angle of $16\deg\pm3\deg$, which favors four rather than two spiral arms for the Galaxy. Combining distances, proper motions, and radial velocities yields complete 3-dimensional kinematic information. We find that star forming regions on average are orbiting the Galaxy $\approx15$~\kms\ slower than expected for circular orbits. By fitting the measurements to a model of the Galaxy, we estimate the distance to the Galactic center $\Ro=8.4\pm0.6$~kpc and a circular rotation speed $\To=254\pm16$~\kms. The ratio $\To/\Ro$ can be determined to higher accuracy than either parameter individually, and we find it to be $30.3\pm0.9$~\kmsperkpc, in good agreement with the angular rotation rate determined from the proper motion of \SgrA. The data favor a rotation curve for the Galaxy that is nearly flat or slightly rising with Galactocentric distance. Kinematic distances are generally too large, sometimes by factors greater than two; they can be brought into better agreement with the trigonometric parallaxes by increasing $\To/Ro$ from the IAU recommended value of $25.9$~\kmsperkpc\ to a value near $30$~\kmsperkpc. We offer a "revised" prescription for calculating kinematic distances and their uncertainties, as well as a new approach for defining Galactic coordinates. Finally, our estimate of \To\ and of $\To/\Ro$, when coupled with direct estimates of \Ro, provide evidence that the Milky Way's dark matter halo is as massive as that of the Andromeda galaxy.

In the statement above, only symbols have been altered from two single quotes (which interfered with Wiki code) to a double quote.

If this is not adequate at this time, it will be necessary to wait for the formal publication.

Thanks!
Klabbas (talk) 18:39, 27 January 2009 (UTC)

Sun-Overview

{{editsemiprotected}}

"The solar constant is equal to approximately 1368 watts per square meter at a distance of one AU from the Sun (that is, on or near Earth). Sunlight on the surface of Earth is attenuated by the Earth's atmosphere so that less power arrives at the surface—closer to 1,000 watts per directly exposed square meter in clear conditions when the Sun is near the zenith." This doesn't seem to be correct. At least one of these numbers must be incorrect for the amount of watts per exposed square meter.

"Space based solar energy has long interested NASA and others in the space community because solar energy is eight times stronger in space then it is after it has passed through the atmosphere." Source: http://blog.wired.com/wiredscience/engineering/index.html
—Preceding unsigned comment added by Funkyfu (talk • contribs) 09:20, 15 January 2009

The article is correct. One factor is that in space you almost never get "behind the planet", so you enjoy sunshine 24 hours a day, not just an average of 3 or 4 hours. Putting solar panels in space is not only stupid, but ridiculous, though. What would happen if someone hacked into the beam controls and wiped out Detroit? That is why space based systems have never been developed. They are not needed, and are horribly problematic. The movies Dr. No and Diamonds are Forever use these death ray themes. 199.125.109.37 (talk) 20:45, 18 January 2009 (UTC)

James Bond movies aren't a reliable guide to technology. What would happen if someone hacked into the beam controls is pretty much nothing, beyond the loss of power. The power density of the microwave beam wouldn't be that much brighter than sunlight.

Space-based solar power hasn't been developed yet because thus far it's even more expensive than ground-based solar.

—WWoods (talk) 01:40, 19 January 2009 (UTC) the variables of Optical resolution, space distance and time preclude the ability to postulate an accurate math construct of the model proposed here

Link to Nemesis article?

I was surprised to find no mention of the Sun's hypothetical companion Nemesis (star), or any links to its article. I know that its existence is debatable, but as a still unsolved question that relates directly to the sun, I'm surprised to not see it. Should a link be added somewhere, possibly in the 'see also' section? 155.68.113.210 (talk) 21:12, 19 January 2009 (UTC)

not bad idea at all —Preceding unsigned comment added by UnionWorker (talk • contribs) 05:20, 1 February 2009 (UTC)

Additional citations needed?

I just reverted an IP that messed up the intro sentence and now notice that there's a "more references needed" tag on the top of this article. So I scroll down and notice that several paragraphs are totally uncited. Does that mean this article is falling away from FA status? I'd recommend adding some before someone will bring up a review. --Andrewlp1991 (talk) 02:07, 22 January 2009 (UTC)

Power density in the core

In the section Core a power density of 6 µW/kg is given for the sun and it is compared to a rate of 1.2 W/kg given for the human body. By simple math this is a factor of 200 000 and not "a million times greater" as written in the text. What is the truth? 85.179.248.148 (talk) 11:46, 26 January 2009 (UTC)

Because of the protection, I can't edit the template, there is an error with the volume.

I am calculating how to find the gravitational pull of objects and the math doesn't work out with what is listed, and if you follow the source cited for the volume, it is wrong anyway. It should read 1.412*10^18 KM^3, or 1.412*10^21 M^3 to keep it in line with the rest of the box. Because of the protection, I can't edit the article.

Proof: As per the page here on the Earth's gravity, you can get the radius, in meters, of the object by taking the volume in KM^3, multiply that by 238,732,415 and take that to the power of 1/3

Using the 1.412*10^27 as the volume cited in meters, you get (1.412*10^27 * 238,732,415)^(1/3) = approx 695,956,394,235.4 meters

695,956,394,235 vs the 695,500,000 as quoted in the article is WAY off.

The gravitational pull of the Sun should be about 274.1 meters per second per second. If you take that "radius" I calculated above and plug it into the formula of (mass in kg * G) / radius in meters squared where G = 6.67427x10^-11 you get about 0.000274 meters per second. That would be less than the moon.

If you use 1.412*10^18 KM^3 in the formula to get the radius, you get about 695,956,394.2. That is closer to the 695,500,000 quoted as the radius.

Plug that back into the formula for gravitational pull and you get about 274.09 meters per second per second. That is much closer to the 274.1 that is quoted in the Earth's Gravity article.

Therefore, could someone with the proper editing level please change the volume to 1.412*10^21 M^3 please?Ciderbarrel (talk) 20:02, 1 February 2009 (UTC)

Sun volume

{{editsemiprotected|Template:Solar System Infobox/Sun}} The volume here is indicated as 1.412×10^21 m³, and in the reference at nasa it is listed as 1.412×10^18 km³. You cant go from km^3 to m^3 by just multiplying 10^3, this is qubic km and qubic m, you have to multiply 10^9. The correct volume of the sun is 1.412×10^27 m³

Question: Could you please put on here the exact page from NASA which you got that? Thanks. Leujohn ^(talk) 12:58, 9 February 2009 (UTC)

The nasa page is the fourth reference in the article (wich is linked from the volume data). The adress is: http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sun&Display=Facts&System=Metric

 Fixed Template:Solar System Infobox/Sun as it was clearly off by a factor of a million, thank you for the heads-up. It seems that error was unfixed since 1 February. I also added the same NASA cite for the mass figure. 84user (talk) 00:18, 10 February 2009 (UTC)

Note: The infobox's Rotation velocity had a {{Fact}} "citation needed". I made a small fix and added the above NASA cite as support, but used this archive.org cache because the NASA page is returning access errors at the moment. 84user (talk) 00:52, 10 February 2009 (UTC)

Turning causes burning

Hi,

I find it strange that there is no information on this topic that the burning of the sun is caused by it's extreme high rotation speed, like the center of the earth.

best,

Michel sharp (talk) 21:15, 4 March 2009 (UTC)

I'm no expert on stars, but I don't see how the rotation speed would make the fusion reactor go (I'm assuming that this is what you meant by "burning". The sun is a gravitationally-contained fusion reactor, with the high pressures at the center allowing fusion. The energy released from the fusion pushes outwards on the sun, such that it doesn't gravitationally collapse because the outward forces from fusion (and some rotation, though I think that's a much smaller term) equal the inward forces from gravity.

I'm not sure what you're saying about the center of the Earth: it rotates very slightly faster than the rest of the planet, and no fusion reactions are occurring down there.

Awickert (talk) 16:33, 22 March 2009 (UTC)

Rotation causes gravity and if you spin something very hard it's starts to burn. If our solar system is turning, the center of it turns the fasted while the loose objects (planets) are turning along with the sun and are slowing down. And when you look at what speed the planets turn around the sun, while they are losing speed, the rotation of the sun must be immense. On the 'Nuclear fusion' page it says; "Nuclear fusion occurs naturally in stars" can't it be that the friction of heavy rotation causes these fusion reactions. In the same sense the earth is still a drop of hot lava spinning around with at the center a small core that rotates (vibrates) at very high speed while the earth's crust is cooled down and turns much slower.

This idea seemed logical to me so I thought I would find a reflection of it on the sun's wiki page, but I'm not an expert and this idea is probably a bit to simplistic.

Michel sharp (talk) 11:15, 24 March 2009 (UTC)

Nope, no-can-do. Rotation does not cause gravity, and spinning doesn't cause burning (unless there is enough friction) - in any case, we're talking about nuclear fusion instead of fire. The planets aren't slowing down much at all (for practical purposes, they aren't), and their velocities are based on conservation of angular momentum. Fusion is caused by the high pressure at the center of the sun. Your statements about the Earth's interior (on which I know more) aren't correct either; try reading Wikipedia articles on the topic. If you like, I could suggest a couple of textbooks. Awickert (talk) 10:26, 24 March 2009 (UTC)

Ok thx for the information, you may remove my comment/topic from this 'talk' page if you wish.

kind regards, michel

Michel sharp (talk) 14:08, 25 March 2009 (UTC)

No problem. In case you read these ideas somewhere, I'll leave the discussion up, in case anyone else has similar questions. Awickert (talk) 17:22, 25 March 2009 (UTC)

Distance from Milky Way Core

...is reported to be both 26K ly and 24.8K ly in the article. —Preceding unsigned comment added by Mortensi (talk • contribs) 17:37, 10 March 2009 (UTC)

Looks like someone fixed it: I now see 2 instances of "26" (infobox and body) and one "24-26" (lede). They should still probably agree with one another, or at least not give the approximate distance at the top of the range of distances, though maybe that's what the source had; I don't know this offhand, but I will add the info if I get to digging. Awickert (talk) 16:38, 22 March 2009 (UTC)

The sources used in the article say:

• NewScientist [14] (2008) (This is a digest of an article in Mon. Not. R. Astron. Soc.A): Old figure 26,100 LY; new figure 27,400 LY
• AnnRev [21] (1993): 26,100 LY
• Astrophysical Journal [22] (2003): 25,900 LY
• Astron. Nachr. [23] (2004): 25,900 LY
• Astrophysical Journal [24] (2005): 25,850 LY

From what it looks like, consistent recent results place it at about 25,900 LY, and that number should be used, unless we see some good reason to jump up by 1500 and use the 2008 paper, linked here. Awickert (talk) 17:08, 22 March 2009 (UTC)

Solar system age

The age in the first paragraph of "Life Cycle" seems to be a well-intentioned but incorrect synthesis. The 4.567 Ga "Age of the Earth" given in the note is actually the age of solar system from radiometric dating of the earliest known solar system material: see the article on Calcium-aluminium-rich inclusions, which the note mentions. I propose that the note be deleted, and the age be given as 4.567 Ga, with a reference to the paper that gives this date. I've got the ref right in front of me, so I'll do it, I just want someone else's approval to say that I'm not wrong in changing this. Awickert (talk) 17:19, 22 March 2009 (UTC)

OK - no objections. Gone, baby. Tell me what you think (especially if you don't like it); I'm not sure if I like the way I said it. Awickert (talk) 08:18, 28 March 2009 (UTC)

Cultural history language correction

The article romanizes the character 日 as nichi in Japanese, but in modern Japanese nichi almost always refers to days or dates (there are only a few exceptions to this, such as 日本 - nippon for "the land of the rising sun" - or 日曜日 - nichiyōbi for literally "sunday"). A Japanese person referring to the Sun would read the character as hi instead. --CrippledPidgeon (talk) 00:26, 23 April 2009 (UTC)

Yes, 日 should be "hi". Awickert (talk) 03:45, 26 April 2009 (UTC)

Great Eastern Sun

• [4] This is the socalled Great Eastern Sun.

Am I allowed to put it here? Or does the text mean that it is forbidden?

-- 88.75.200.76 (talk) 10:54, 3 April 2009 (UTC)

Don't see how it would help much here - if we include this, why not every sun-symbol? Awickert (talk) 03:45, 26 April 2009 (UTC)

"Ending all human life"

"The increase in solar temperatures is such that in about a billion years, the surface of the Earth will become too hot for liquid water to exist, ending all terrestrial life."

Really? You presume to say that you know what evolution will produce in a billion years? That not only natural selection will not produce organisms able to live in progressively hotter temperatures, even as the slow transition of the surface temperature crosses the boiling point, but that the descendants of humans and any other intelligent species will not devise a way to live in such a world? zafiroblue05 | Talk 07:05, 17 November 2008 (UTC)

Well to be fair this is the current standard scientific position. Once liquid water is no longer present on the planet complex life will probably not survive. There may still be microbial life left though. Exactly when this will occur is not known, that it will occur though is not in doubt. This is still an area in which more work needs to be done but science fiction aside most if not all complex life on earth will be gone at some point as the temperatures rise. Antarctic-adventurer (talk) 21:15, 6 May 2009 (UTC)

Relative volume of the Suns core.

If the radius of the core is 0,2 solar radii, its volume is 0,2^3 or 1/125 solar volumes, so much less than the 0,1 given in the article. Willem Schot —Preceding unsigned comment added by Wschot (talk • contribs) 12:49, 3 May 2009 (UTC)

Agreed - it would have to be approx. 0.46 solar radii for this to be true. I'll base this on the cited source (volume), and change the radius reported in the article accordingly. Awickert (talk) 22:52, 9 May 2009 (UTC)

Well, it seems that the interwebs, disagree, so I am pinning radius at 0.2 based on this Science article, and changing things accordingly. Awickert (talk) 23:09, 9 May 2009 (UTC)

Alternative solar models

Having done some reading on the subject, I've come to realize there are a significant amount of alternative solar models, some of which are backed up with fairly presentable observations. I was therefore surprised when I typed "Sun" into Wikipedia that could find no reference on that page linking to existing alternative models.

Such a reference would be entirely appropriate considering the difficulties listed with the present accepted model.

For example, after reading references throughout the web referring to an electric solar model, I was surprised to find that Wikipedia had a dearth of information on the subject.

However strongly opposed many mainstream scientists are to these non conventional approaches, it is nonetheless disturbing that no reference is made to such alternatives in Wikipedia.

Might I be missing something? Could someone with better research skills direct me to alternative solar models in Wikipedia? —Preceding unsigned comment added by Esteban (talk • contribs) 16:49, 5 May 2009 (UTC)

Please keep your fights on the baut forum. Wikipedia is not the place for them.Geni 22:48, 5 May 2009 (UTC)

I'm sorry, although we both seem to be communicating in English, your brief comment appears directed somewhere else entirely. Again, question: Why is there no mention of alternative solar models on the Sun reference? Do these not exist? --Esteban (talk) 05:39, 6 May 2009 (UTC)

I think that the reason is that your first comment came off on the aggressive side: phrases like it is nonetheless disturbing don't rub volunteer editors the right way. I'm no expert here, but my best guess is that these theories are not given much weight by scientists, and are therefore (per WP:WEIGHT not mentioned here. A good way to proceed would be to lay out peer-reviewed scientific sources that give the alternate models. Awickert (talk) 08:19, 6 May 2009 (UTC)

As a layman I appreciate that there is an accepted scientific model, but sometimes 'alternative' theories become popularized and perhaps at least a reference to them as debatable (or refutable, if you prefer) seems necessary in an encyclopedic article. For example, a theory of a rigid iron structure of the sun might be alternative, but it is mentioned in passing in Plimer's Heaven and Earth: global warming, the missing science. A lay reader like me relies on Wikipedia to give me at least some information to understand whether this is theory is part of the discussion or is marginal. thanks. --Richardson mcphillips (talk) 23:11, 9 May 2009 (UTC)

Hi Richardson. Sorry I haven't responded - the truth is that I don't really know about this stuff. If you could point me to a scientific paper referenced by the book, I'd be willing to try to track things down. Awickert (talk) 04:43, 12 May 2009 (UTC)

Esteban, you've mentioned that there is a "significant amount of alternative solar models". It's important to keep in mind in order to merit inclusion within an article such this one, what is important is not the quantity of alternative theories, but the amount of support each model has received from the scientific community. Although I have not worked on this article, I would imagine that a section on alternate theories would probably end up being nothing more than a list or a hodge-podge paragraph with one sentence dedicated to each alternative model, which wouldn't really be beneficial to the article. If you've come across a few alternative models that you think should be mentioned, perhaps you should start an article such as alternative solar models or list of solar models or some such? --Cryptic C62 · Talk 04:07, 12 May 2009 (UTC)

Verification

The article seems to contain too many unverified claims. It is vital either to verify all of them or delete if unverifiable. Otherwise the article may go to FAR. SkyBon^{Talk\Contributions} 09:38, 27 May 2009 (UTC)

Should the title be "Sun" or "Earth's Sun"

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

Consensus reached: article is fine where it is. Awickert (talk) 03:06, 31 May 2009 (UTC)

---

see also: Talk:Moon#Should the title be "Moon" or "Earth's Moon"

Should the title be "Sun" or "Earth's Sun". I prefer Earth's Sun to make it clearer that we are not talking about stars in general. You could argue that "Sun" is clear enough, but why not make it clearer, you could argue that "Earth's Sun" looks weird, but so what.--Emmette Hernandez Coleman (talk) 02:55, 26 April 2009 (UTC)

Anyone with an opinion of argument about this, please post it.--Emmette Hernandez Coleman (talk) 14:38, 26 April 2009 (UTC)

"Sun", as that is the proper name in English. "Earth's Sun" would incorrectly imply that other stars could also be called "suns", when they cannot. (There is only one "Sun", that being the star at the centre of the Solar System.) --Ckatz^chat_spy

My original wording of my first comment in this section, "I prefer Earth's Sun to make it clearer with sun we are talking about." was poor, I have updated it to say what I meant to say,"I prefer Earth's Sun to make it clearer that we are not talking about stars in general." sorry for the PARTIAL misunderstanding, it was my fault.--Emmette Hernandez Coleman (talk) 03:24, 26 April 2009 (UTC)

Same reply, though. "Earth's Sun" would still make an incorrect implication. --Ckatz^chat_spy 03:37, 26 April 2009 (UTC)

Agree with Ckatz: ours is Sun, all others are stars. Awickert (talk) 03:40, 26 April 2009 (UTC)

According to Wiktionary any star can be called a sun, so the implication is correct--Emmette Hernandez Coleman (talk) 12:03, 26 April 2009 (UTC)

Hmm - so maybe it's one of those capital letter things again: Sun/sun. Awickert (talk) 16:42, 26 April 2009 (UTC)

Awickert, you are correct wiktionary:Sun, the title should be changed to "Earth's sun", not "Earth's Sun"--Emmette Hernandez Coleman (talk) 17:16, 26 April 2009 (UTC)

They do have that definition on the disambiguation page. General Wikipedia policy is to give the least-qualified name to the primary usage of the word. The alternative seems to be changing it to "The sun" or "Earth's sun", and making "Sun" a disambiguation page. As for browsability, I don't see the advantage in that. We could refactor the disambig page to put the star from another solar system at top. Awickert (talk) 17:53, 26 April 2009 (UTC)

Why would "Sun" have to become a disambiguation page?--Emmette Hernandez Coleman (talk) 18:07, 26 April 2009 (UTC)

See comments on Talk:Moon. Awickert (talk) 18:11, 26 April 2009 (UTC)

Almost all common words in English have more than one meaning. This is why Wikipedia has adopted a principle of "least surprise" in the naming of articles. If someone finds an article named Sun, 99% of them would expect the article to be about the star that Earth orbits. Most people would be surprised if the article were about anything else. Likewise Star is an article about stellar ojects, not about actors and actresses. The article on Earth is about the planet, not about soil. When a noun has a widely known usage with a proper noun sense, that meaning is the one most likely to be expected by a reader. If Wikipedia were to abandon the principle of least surprise, nearly every article with a common noun name would have to be renamed. Consider that a plant can be a manufacturing facility; hat can be a diacritical character in writing; book can mean a section of a larger literary work; and chair can mean the head of an organization or group. The article titles do not have to be 100% precise, but merely 100% descriptive. --EncycloPetey (talk) 21:53, 26 April 2009 (UTC)

The Sun is the dominant body in the solar system, so doesn't really belong to the Earth, so Earth's Sun would be a bit wrong, and calling it Jupiter's Sun would be equally valid. However renaming Earth to "The Sun's Earth" would be more correct that what the OP suggests. Martin451 (talk) 22:11, 26 April 2009 (UTC)

About the Sun not really belonging to Earth, does your home not really belong to you because it is much more massive then you, would it be as valid to call it your T.V.'s home as it would to call it your home.--Emmette Hernandez Coleman (talk) 22:55, 26 April 2009 (UTC)

Looking at dictionary.com's Sun, it would be (and should be) technically improper to call other stars a Sun. -- Kheider (talk) 09:56, 30 May 2009 (UTC)

I can't see any argument for Earth's Sun. Why not Jupiter's Sun? Jupiter is bigger. Why waste characters on a fundamental topic? Earth's sun already redirects here, and capitalizing sun when using it as a synonym for star is wrong.Novangelis (talk) 00:50, 31 May 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Lead sentence

The lead sentence reads: "The Sun (Latin: Sol), a yellow dwarf, is the star at the center of the Solar System." I have modified this to read: "The Sun (Latin: Sol) is the star at the center of the Solar System." My reasons: (i) the insertion of "yellow dwarf" is a detail that does not belong in the opening sentence, and is already covered adequately in subsequent sentences; and (ii) the page to which it links, G V star, is a stub that needs work. Timb66 (talk) 22:46, 12 June 2009 (UTC)

Summer and Winter

The head of the article mentions Summer and Winter when talking about ~the sun's distance to the earth. Yet those seasonal notions are only relevant relative to one's hemisphere. Shouldn't the article be more precise as to which "summer" or "winter" it is referring to ?

Since this article is "semi" protected I am unable to indicate which hemisphere's season the article is indicating myself. Please someone who has the appropriate authority make the necessary correction ?

PS : I also happen to live in the same hemisphere where earth happens to be the farthest from the sun when it's summer for me, as stated in the article, so it's not personal !

PPS : Is there really a relevant relation between the equinoxes/solstices - the min/max (0°/~23°) angle between the earth' rotation axis and the earth/sun orbiting plane) and the major/minor axis of the earth/sun orbit - except for sensationalism - because the northern summer happens to be further from the sun than when it is winter in the northern hemisphere - contrary to popular belief ?

However, despite my opinion this might be irrelevant, my proposal is simply to append a "northern" qualification to the initial "summer" part in the article.

Ivan Scott Warren (talk) 01:10, 19 June 2009 (UTC)

I have altered the bit to

from a minimum of .... on 3 January, to a maximum of ..... on 4 July.

I don't know whether this is too much detail, but it is better than say summer in the northern hemisphere etc. Martin451 (talk) 01:20, 19 June 2009 (UTC)

In answer to your question, there is no relationship between equinoxes and the earth-sun distance. See Earth's orbit, Precession (astronomy) and Milankovitch cycles Martin451 (talk) 01:38, 19 June 2009 (UTC)

Magnitude

• 4.86 The Magnitude of the Sun, the Stellar Temperature Scale, and Bolometric Corrections. Kuiper, G. P. 1938
• 4.85 Stellar parameters 1986
• 4.84 A planetary system for Gamma Cephei? 1989
• 4.84 Main-sequence photometry, color-magnitude diagrams, and ages for the globular clusters M3, M13, M15, and M92 1970
• 4.83 Three Double-lined Class B Spectroscopic Binaries 1925
• 4.82 Sun Encyclopedia of Astronomy and Astrophysics, 2000
• 4.81 Model atmospheres broad-band colors, bolometric corrections and temperature calibrations for O - M stars 1998

Now sombody has to choose one.--Stone (talk) 07:32, 25 June 2009 (UTC)

Quote 'em all (1970+) and write ~4.83 (or whatever is the rounded average).Headbomb {^ταλκ_{κοντριβς} – WP Physics} 08:02, 25 June 2009 (UTC)

mass

The quoted number Sun, which by itself accounts for about 98.6% of the Solar System's mass looks strange Physics and chemistry of the solar system by John S. Lewis gives 99.9%.--Stone (talk) 07:54, 25 June 2009 (UTC)

• The Sun contains 98.85% of the mass of the solar system but only about 2% of its angular momentum
• the entire mass of the solar system — 99.86 percent — is that of the Sun.
• Whereas more than 99.9% of the total mass of the solar system is concentrated in the Sun, more than 99% of the angular momentum
• The Sun contains almost 99.9% of the total mass of the solar system.
• The total mass of the solar system is 1.9918- 1030 kg, of which 99.86% is contributed by the Sun.
• Since the Sun accounts for 99.6% of the mass of the Solar System

I suspect that depends on how exactly you define "solar system". Do you include only the major bodies or all the interplanetary gas, the Kuyper belt, and the Oort cloud? I would also assume that the total mass of the solar system is not known that well.... --Stephan Schulz (talk) 09:54, 25 June 2009 (UTC)

Brightness of Core

So, if you imagine for a moment that the core of the sun was visible from earth, how bright would it look? —Preceding unsigned comment added by 142.161.170.82 (talk) 23:35, 29 June 2009 (UTC)

Evidence for fusion

Question for the experts:

What (if any) actual experimental evidence do we have to support the idea that the core of the sun contains hydrogen, and that the primary source of energy is fusion? There's no cite, and no explanation -- and I haven't been able to find anything elsewhere. Ungtss (talk) 06:06, 6 December 2008 (UTC)

Question #2: It is mentioned that the photon travel time is something like 10,000 years to 170,000 years from the core to the surface. It is said that a photon is absorbed and re-emitted multiple times before it reaches the surface. What is the evidence that the 'same photon' is being absorbed and re-emitted? Slight explanation will benefit us. 57.67.164.37 (talk) 08:07, 17 December 2008 (UTC)

Answer to Question 2:: It's not the "same" photon. It's just that the energy given to the body it was absorbed is then re-emitted, one could see in a way that it's the same energy, thus the "same" photon. But, in reality, it's a new photon because the energy levels have changed. The question is really one of semantics. —Preceding unsigned comment added by 86.133.137.225 (talk) 18:47, 1 July 2009 (UTC)

Question #1: First, you might go to NASA's site and explore the data from project SOHO (There are articles in Wiki about it...). Other evidence is found in the data from other probes, such as Galileo. One can draw quite a bit of evidence for what is inside a star by examining what is inside the gas giants. Much has been detected through filtration of the light waves eminating from the planets and the star, compared to what we learn about this planet through our terrestrial satellites. The deeper essence of your question enters into my own research area, that being the helium content of the sun. This is because I have contentions with continuous fusion as the power source and predict we will someday reside to stars powered by pulsed fusion. Much of this concept is supported by research we now have about Bose-Einstein Condensates (BEC's) and superfluid ⁴He that forms BEC's, albeit not famously, as quantum vortices. The purposes for my own research involves a somewhat wide scope of astrophysics, but tends to interleave with nuclear power research, so to prove one area experimentally will likely evidence the other as well. DrCWho (talk) 14:12, 9 July 2009 (UTC)

Revision 301516691

For this revision I made, I meant to say '/* Observation and eye damage */ how-to guide-ish. Mainly the last paragraph, but a bit in second para after its cited content as well. last para's source is listed as "juvenile nonfiction"; is there a better source?' (For the last issue, see Google Books.) --an odd name 08:01, 11 July 2009 (UTC)

Sun or The Sun

I'm sure that the Sun's astronomic name is not "the Sun", but merely Sun, as it is simply the local star in our solar system (we don't call Sirius The Sirius and we don't call Alpheratz the Alpheratz).

If what I'm saying makes sense, than this article requires some editing. —Preceding unsigned comment added by 198.96.80.15 (talk) 15:19, 25 April 2009 (UTC)

Hi, my first edit so sorry if I've done it wrong. "The Sun (Latin: Sol), a yellow dwarf, is the star at the center of the Solar System." Shouldn't this read "the center of "our" Solar System?

Yes. Furthermore, the star in question is actually called Sol. The star Sol. —Preceding unsigned comment added by 74.68.112.18 (talk) 01:13, 8 July 2009 (UTC)

The article states Use of "Sol" as a name for the Sun is largely confined to works of science fiction.[164], there is an error here. The quoted reference states that the term Sol is used by scientists and this is correct. The term Sol is used by scientists when discussing or comparing Sol with other stars. Sol is accepted as the proper name of our star just as Musca domestica is the proper name for the housefly. —Preceding unsigned comment added by 62.49.71.10 (talk) 09:57, 24 July 2009 (UTC)

almost. Galilleo, for instance, refers to the sun as "Solis" rather than "Sol" meaning "the Sun" rather than the roman god of the same name from which our word for sun derives. This is in contrast to "Jupiter", which he refers to as is. I can think of many fascinating ecclesiastical reasons why Gallileo would do this, but thats not within the scope of this article. perhaps if he knew of other gas giants we would call them jupiters, after all he refered to the moon as "luna", but thats definately OR.Outerstyx (talk) 16:57, 11 August 2009 (UTC)

Contradiction Tag

Someone place a contradiction tag in the article with regards to the absolute magnitude in the right-hand box. This tag is now in the backlog for the Category:Self-contradictory articles. Since this article is semi-protected, would someone who has access, please review the information and/or contradiction and either fix and remove the tag, or if no contradiction exists, please remove the tag so the backlog can be cleared. Thanks much! Kjnelan (talk) 18:06, 17 July 2009 (UTC)

How many languages use the word "Sol" for the Sun?

Not sure that this issue is of central importance to what is an article about the sun, not linguistics, I've taken the bold step of moving a lengthy list of languages that use the word "Sol" for the Sun to a footnote. It could be restored; I'd like to hear if people think it belongs in the main section.hgilbert (talk) 00:33, 20 July 2009 (UTC)

Who exactly calls the Sun "Sol" in English? When have you ever heard it used, apart from in scifi novels? Your alteration gives the impression that the name Sol is used for the Sun in English as a matter of course. Now I have no doubt that some written sources have used the name and that dictionaries across the English speaking world have cited the definition, but it is not in any way common usage in English and this article should reflect that. Serendi^podous 07:33, 20 July 2009 (UTC)

Let's stick with verified sources. It is an accepted usage and there is no indication that it is obscure or rare in the dictionaries I cite. We have no source that claims it is special to sci-fi novels. hgilbert (talk) 13:04, 20 July 2009 (UTC)

Dictionaries are not good for determining the prevalence of words in any language. All they do is say that someone, somewhere, wrote that word down using that definition. One mention in a thousand years is good enough for a word to end up in a dictionary. Serendi^podous 13:47, 20 July 2009 (UTC)

the reference for the section about Sol being restricted to science fiction actually states "However, hidebound by tradition as we are, you generally only see scientists, nerds, and science fiction fanboys - wait, I'm being redundant. Well, you get the point; most people still just call it the sun." The same source also say's "They are (Sol and Luna), however, pretty much the only proper names in common use for these two stellar bodies among English-speaking folk." Although why straight dope is being used as a reference is beyond me.Outerstyx (talk) 16:58, 11 August 2009 (UTC)

Who first regarded the sun as a star?

The article is well-written, but it misses an information. Who first regarded Sun as a star, and stars as suns? —Preceding unsigned comment added by 83.24.178.111 (talk) 21:00, 11 August 2009 (UTC)

The first time the Sun was regarded as a star (in the modern sense of the word) was in the 1850s with the advent of spectroscopy. I believe Fr. Angelo Secchi was the first person to make that connection, though I don't know for sure. Serendi^podous 10:18, 12 August 2009 (UTC)

"0.3 watt per m3"

The calculation is not consistent. The actual valvue should be higher, do the math!

Regards, Bart Bozon —Preceding unsigned comment added by 62.234.183.218 (talk) 17:47, 26 November 2008 (UTC)

I second this. I did the calculation with the numbers given for core radius and solar output and got 35w/m3. -- Grady

Off-topic and science-challenged rant collapsed

68.231.190.2 (talk) 08:01, 14 May 2009 (UTC) The entire discussion of the sun, beginning with einstein theory, which was first postulated by lorentz, which he discarded because it was incorrect, was the right thing to do. The sun , like all the other physical bodies, has resonant frequencies, which vibrates as it passes around the galaxy at about 200 meters per second, its resonant frequencies are that of the varying light energies we receive as these vibrations pass through the media that exists between the sun and the two planet system, the moon and the earth. In the days before the particle theory of light which has been taught for a hundred years is BS, The substance filling the space was once refered to as aether, a complex mixture of materials through which all vibrations in the electromagnetic spectrum are made up of. This substance is everywhere, thus ( The wave theory of light ) new discoveries from the colliders of more than 100 new materials in existence, occupying all space in the solar system, completely destroy the particle theory of light,the physical bodies in our solar system compose around 1.4 % of the solar systems mass. The sun is left without true description because we have yet ti develop materials that will not perish in its atmosphere, nor will we try if we believe the einstianian garble that dominate the pseudo-scientific/ quasi-medical/ legalinsurancefraud/academic caste system that is nothing but academic venture in the business to make money. They say anything. When you descend to the point of teaching theory as fact, then you have lost sight of true education, and are no longer fit for the use intended. The internet can teach a kid in a week what he can learn in a symester, without turning him into a drunk, junkie, or hooking him up with a sexual predatory for a professor. Academia is dead, its time to bury it and start over with learning and data mining techniques. La regime de la pedagogque is over. The information revolution will change the world. all the land is holy land and all the children are equal " goyim " is not a word, stop treating us like one---to the directors of wikipedia

Same problem with the numbers here (not with the theory, like the previous post!) I added an "expert-needed" notice to that section... the numbers are odd. I have my own consistent numbers, but they might be wrong as well. Probably there are uncertainties also. We really need an expert for this task, not some self appointed one... (been there, done that, not again!) Rnbc (talk) 13:16, 4 August 2009 (UTC)

I also agree that the power density is not correct. The 0.27 Watts per cubic meter represents an overall average of the Sun. I'm getting 33.9 watts per cubic meter in the core. The point that humans generate substantial more power per cubic meter is still valid. -- Charlie Moquin —Preceding unsigned comment added by 97.119.155.72 (talk) 05:44, 1 September 2009 (UTC)

More user friendly units of measure please

I found myself having to pull out the calculator repeatedly to make sense of the units in this article. The worst offender is the description of the core whose units are given in solar radii!!! That's self referential! It would be good to include more conventional units (miles and km) in many places. I would even suggest that the speed of the sun's rotation around the galactic center be translated from km/s into both km/hr and miles/hr, and that Kelvin be translated into both C and F. Keep mind that not only scientist read an encyclopedia article about the sun. American (and metric) kids do too and it would be nice if this article were more approachable. Yes translating the units in this way results in huge numbers but it also helps lay people grasp the magnitude of the sun. Cshay (talk) 21:22, 7 July 2009 (UTC)

I'm glad you're complaining, Cshay, this thing is *not* supposed to be a science research paper. (Likewise, too many of the references are not suitable for intelligent laypeople - not even science undergrads.) But it's easy to forget that while trying to keep things up to date.
I'd encourage you to try to estimate rather than whip out the calculator. If it helps, K is very close to C for large temperatures. A km is very close to 2/3 of a mile.
It's hard to write science articles that are accurate, up-to-date, and readable for the average educated person. (And ... at what level?!) Definitely, too many tech/science articles on WP are too complex. (Many of the bio articles make me gasp.) But science uses hundreds of units, and it's hard to be 'science-literate' without grasping the common ones. Twang (talk) 21:32, 25 July 2009 (UTC)

I disagree. And besides this has been discussed before. If we start putting all sorts of different unit conversions in for every measurement we will get an extremely cluttered article. This makes it highly unreadable. Science works in SI (aka metric). All over the world. There are standard units sometimes used in a particular field outside metric (e.g. astronomical unit which is the earth/sun distance) and it is appropriate to use those figures in an article. For example "The sun is 149.6 million km (1 AU) from the Earth". Also including miles, yards, feet, centimetres (or whatever takes one person's fancy) in brackets is just silly. If you need an accurate figure for a calculation then you are going to use the SI number. Other than that, in astronomy you can probably look at 15 million K and say "that's hot". Jim77742 (talk) 05:21, 30 July 2009 (UTC)

It's been discussed before? Well don't even get me started on my dislike for archivebots. They lead to repetitious discussion pages don't they? Anyway, you are looking at this issue as a scientist and also as someone concerned with clutter? How about being concerned about the 95% of the audience who are not scientists? How come the worldbook encyclopedia I read as a kid didn't use Kelvins in place of Celcius? That's right, and it's because they were trying to make something readable by lay people. It seems a cabal of scientists has banded together and decided that Wikipedia will read like a university research journal, everyone else be damned (this is not the only article with this problem) Cshay (talk) 06:07, 18 August 2009 (UTC)

Short scale or long scale?

I'm guessing this uses the short scale but aint the long scale more appropiate for scientific data? It has a constant with an homogenous proportion unlike the short scale, just like the metric system is better to handle data than the imperial system...Undead Herle King (talk) 04:28, 6 September 2009 (UTC)

Science uses short scale. As far as I'm aware the long scale is only really widely used in France these days. Serendi^podous 08:51, 6 September 2009 (UTC)

1/1250th of a revolution?

In the middle of the third paragraph in section 1 ("The Sun's motion and location within the galaxy"), you can read:

>>It takes the Solar System about 225–250 million years to complete one orbit of the galaxy (a galactic year),[32] so it is thought to have completed 20–25 orbits during the lifetime of the Sun and 1/1250th of a revolution since the origin of humans.

1/1250 of a revolution gives at most 250 million years / 1250 = 200 000 years elapsed since the origin of humans. Doesn't it look more like the actual number of revolutions completed since then is either 1/125 or 1/250? By the way, they could be written, respectively, as "one 125th" and "one 250th", but not "1/125th" (that could even be interpreted to mean the reciprocal of one 125th, i.e., 125) and "1/250th". —Preceding unsigned comment added by 77.209.55.88 (talk) 16:06, 8 September 2009 (UTC)

I've removed the reference to the origin of humans as it isn't a useful astronomical measure. There are also uncertainties about that date relating to how we interpret the fossil and DNA evidence of our ancestors. --TS 22:30, 8 September 2009 (UTC)

Edit Request

{{editsemiprotected}} The radius and circumference data is incorrect, check the linked citation for the correct values. I am just going to assume all the other data about The Sun in this "featured article" is also incorrect, but I'm not going to bother with it since this is a "protected page". Nice job ruining hundreds/thousands of children's school reports ya small-brained amateur nazis, lol. No big deal, just a couple orders of magnitude. Of course these errors would have been fixed in seconds by someone like me if it was not a "protected" page. {{editsemiprotected}}—Preceding unsigned comment added by 71.221.82.241 (talk • contribs)

From what i can see (checking the NASA reference) both radius and circumfence are correct - have you noticed that the figures are in meters - not kilometers? (ie. 10³ larger figures). --Kim D. Petersen (talk) 11:41, 22 June 2009 (UTC)

Not done: Welcome and thanks for the laugh. Your "edit request" is a fine example of why Wikipedia protects this article from being "fixed" by new or anonymous editors. Priceless! Celestra (talk) 14:52, 22 June 2009 (UTC)

Please add an external link to the animated multimedia resource 'The Structure of The Sun' on the Alien Worlds website. This resource was awarded second prize in the UK Association for Learning Technology 'Learning Object Competition 2008'. Please use the following for the link: "An animated explanation of the structure of the Sun, University of Glamorgan" NB.First time request for an edit to a semi-protected page, hope I've submitted correctly, apologies if not. Urbanclearway

Radius and circumference should be expressed in kilometers, see Earth's Physical characteristics for example. <irony>Oh wait, make it in terms of Angstroms, or even better, convert it to hogsehead/kilobyte just to make more sense. </irony> —Preceding unsigned comment added by 84.224.54.171 (talk) 19:51, 11 September 2009 (UTC)

Correction to reference 126

{{editsemiprotected}} Reference 126 needs to have its page numbers corrected. The correct page numbers should be 388-393 instead of 288-293. This can be verified by looking at the Google PDF of this journal at:

http://books.google.com/books?id=9e1C_nqprmsC&oe=UTF-8

71.56.155.182 (talk) 00:03, 23 September 2009 (UTC)

 Done - Well spotted, thanks! ∙ AJCham^(talk) 00:18, 23 September 2009 (UTC)

confused

I am slightly confused why this article has kilometers instead of miles, and Celcius instead of farenheit???? South Bay (talk) 06:41, 24 August 2009 (UTC)

Because it is a scientific article. Science uses metric. Serendi^podous 07:16, 24 August 2009 (UTC)

Some countries don't use kilometers or Celcius and it could be hard for those people to translate.. South Bay (talk) 07:38, 24 August 2009 (UTC)

Far more countries use metric, so that's hardly a compelling argument for using traditional measures. Kiore (talk) 09:52, 24 August 2009 (UTC)

Oh, and what countries are you speaking of?? South Bay (talk) 15:05, 24 August 2009 (UTC)

Countries where the metric system is official (according to the CIA World Factbook) are shown in green.

Everywhere except Burma, the USA, and limited informal use in the United Kingdom. Kiore (talk) 19:24, 24 August 2009 (UTC)

Oh, do you just make up the map yourself??? South Bay (talk) 19:43, 24 August 2009 (UTC)

Metric is the only system that has any kind of international validity. We should try to use proper, grown-up measurements. I always avoid ells, drams, barleycorns, scruples and mutchkins; miles and inches are just as inappropriate. 124.170.123.65 (talk) 14:29, 28 September 2009 (UTC)

The map of countries where the metric system has been officially adopted isn't much use in this context. In science, the Système international is universal. --TS 16:13, 27 August 2009 (UTC)

if you need the miles, don't open this
What about amu's? Are they deprecated for atom masses? Or AU's? Or g/cm3 when we're not trying to be prissy correct like in papers with kg-1/m-3? They're used because they're conveniently sized. We certainly don't use Imperial, though. Sagittarian Milky Way (talk) 17:32, 27 August 2009 (UTC)

Any user is free to copy the article into their userspace, change the units, and post a link to it on this talk page. Sagittarian Milky Way (talk) 17:32, 27 August 2009 (UTC)

Typo spotted

On the second line of the subsection titled "Core" the value for the core temperature seems to be wrong. Currently it reads "close to 13,600,000 Kelvin", while the temperature in "Physical characteristics" is "~15.7×10^6 K". —Preceding unsigned comment added by 86.50.110.124 (talk) 06:25, 1 October 2009 (UTC)

Plages

The plages article is currently orphaned. My Intro to Modern Stellar Astrophysics 2nd Ed, by Dale A Ostlie and Bradley W. Carrol, defines "plages ... are chromospheric regions of bright Halpha emission located near active sunspots". More detail is in the plages article. It seems to me that the section on Sunspots would be the place to mention plages and link to the plages article. Puzl bustr (talk) 14:47, 1 October 2009 (UTC)

Temperature of the Core

This article features two significantly different temperatures for the core of the sun. The infobox gives the temperature as around 15.7 million kelvin, backed up by the NASA fact sheet it references. The main text of the article gives the temperature at 13.6 million kelvin. I'm not qualified to decide which is the right number, but would someone who is please fix this? —Preceding unsigned comment added by 81.107.38.136 (talk) 10:47, 13 October 2009 (UTC)

Consumption of hydrogen is wrong

In the Core section it says:

...converted into helium nuclei every second ... or about 4.4 × 10^9 kg per second,[49] releasing energy at the matter–energy conversion rate of 4.26 million metric tons per second...

These two figures are near enough the same when the first should be very roughly 100x bigger, which suggests a mix up. The second one is probably correct but I don't have a figure for the first. Man with two legs (talk) 17:19, 17 October 2009 (UTC)

According to the Phillips source (Guide to the Sun, Cambridge University Press, 1995, ISBN 052139788X, p. 53) there are 9.2·10³⁷ occurrences of the proton-proton chain each second. Each such reaction uses four protons so the mass rate at which protons are converted into helium nuclei will be

9.2·10³⁷ sec^-1×4×1.007276 amu = 6.2·10¹¹ kg/s or so.

Since the mass of the helium-4 nucleus is 4.001506 amu and the proton mass is 1.007276 amu, each reaction liberates around (4×1.007276 − 4.001506)/(4×1.007276) = 0.68% of the fused mass as energy. So, the total mass conversion rate is 0.68% of 6.2·10¹¹ kg/s, which is 4.2·10⁹ kg/s or so. Multiplying this by c² gives the solar luminosity of 3.8·10²⁶ watts.

Spacepotato (talk) 18:29, 17 October 2009 (UTC)